Looks like a nice upgrade but I don't see and replacement thrust bearings available on HK to fit this unit. Its awesome that HK offer these upgrade items but they need to offer support parts for them as well.
Hi i fitted these in my HK 450 and the mail shaft is now super smooth,i agree that they should have replacement thrust bearings available,if for some reason the bearings should fail i will replace it with the whole kit if needed,great upgrade.Thanks HK
All my outer rings have the same diameter, 11 mm. the only difference is that two of them have different diameter holes in them. Two have a sloppy fit on the shaft, the other two are tight. I am going to have to grind two of the rings smaller so they will turn in the bearing block. Also, can somebody give the correct method of installation? There seems to be a lot of differing opinions on here.
It still won't work because all the races are the same diameter. I don't have two that are 10.8 and two that are 11, they are all 11 mm so they won't turn properly in the bearing block. Also, once together the main shaft is off by a degree or more so the main gear is way off. Can not use blocks!!!
The drawing shows an incorrect assembly order. In order for the thrust bearing to bear the thrust-load, the radial bearings must be fitted into housings first, and then the thrust bearing stack (as shown in the diagram). The assembly is similar to that deployed in the alloy blade holders.
One of the bearing housings has an interference fit, which appears to be intentional, use this bearing housing in the lower position.
Radial Bearings: Use mandrill from a one-way bearing fitting/extraction tool, in conduction with G cramp to gently press the radial bearing into the bearing-housing.
Thrust Bearing: The two race-halves are different one had larger outer diameter, larger inner diameter and thinner* the other has smaller outer diameter, smaller inner diameter and is thicker. Fit the one with the race with the larger outer diameter nearest to the radial bearing, the larger inner diameter provides running clearance between it and the main shaft.
The half with the smaller outer diameter provides running clearance between it and the blade holder.
Brass Washers: place one of these between the top side of the upper thrust bearing and the lock ring, place the other under the lower thrust bearing and the shaft ring/one-way clutch-bearing.
If you got the same diameter thrust halves, just use an exacto knife and lightly cut the housing so the thrust plate outer half will turn with the main shaft. Also make certain that the inner thrust plate does not fit snug to the shaft as it will try to spin with the shaft and soon bind up inside the mounting blocks. As far as alignment, trim a little off the tit that holds the blocks in place on the frame with an exacto knife, or even open the mounting holesa in the frame just a small amount,
The bearings in the drawing have to be changed. The thrust bearing has to take the forces in direction of the main axis. Therefore, the trust bearing has to sit in the outer position. The ball bearing is than only used to center the axis. By the way, its the same in rotor heads with thrust bearings: the thrust bearings is mounted near to blade holder screws to take the axial forces.
The bearing block is not supposed to be tight on the outer thrust bearing races. The outer thrust bearing race is supposed to turn freely insided the bearing block. If the bearing block is too tight, the thrust bearing race will scrub against the alloy bearing block and either get hot and lock up or distribute metal particles inside the bearing. Neither is acceptable. The main shaft bearings prevent side to side movement (proper gear alignment) of the shaft while allowing friction free rotation. The thrust bearings absorb vertical forces (positive and negative pitch changes in the rotor head) and protect the main shaft bearings from these loads. The outer thrust bearing races MUST turn freely in order to work properly. If the bearing block is tight against the outer thrust bearing race, the block is defective and should be replaced. Also, the drawing is incorrect. The thrust bearings are supposed to be on the outside of the shaft bearings. My thrust bearing races are all identical in size, both I.D. and O.D.
You need to install a thin washer between the radial and thrust bearings, one that fits on the outside of the the radial bearing,not the inside.The point of this mod is to transmit the thrust load to blade grip not the radial bearing,these types of bearings are not made to take a side load.The washer makes it so the inner and outer racees of the radial bearing dont hit on the the flat side of the thrust washer,and cause them to drag.
This drawing is wrong, the radial bearing must be fitted into the bearing housing first (interference-fit), followed by the brass spacer shim, and then the thrust bearing race with the larger outer diameter, followed by the ball cage, then the thrust bearing race with the smaller internal diameter.
Thus, when these bearing assemblies are fitted into the main frame:
i) top bearing assembly:… the thrust-bearing outer race faces up directly under the lock-ring* and
ii) bottom bearing assembly:…
Because this part (and the idle pulley - the other red upgrade) are produced by a different manufacturer - Ele RC.
16 thumbs up!
This does work with the HK-450. BUT- when you install the blocks leave them loose at first (don't tighten the screws yet). Then insert the main shaft and make sure it turns free - then tighten screws. Not sure why Klaus couldn't get this to work. But mine came with 2 sets of thrust bearings each with one smaller and larger I.D. See diagram in the "discussion" tab. Must give 4 stars because screws not included with kit (M2x6 non-tapping).
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1 thumbs up!
These are a nice upgrade. 4 stars because there are no screws. Do NOT use same screws used in the plastic bearing blocks! Get straight thread screws. When installing put the thrust washer assembly under the radial bearing on the top and on top of the radial bearing on the bottom. The thrust bearing washers/races on mine turned fine inside the bore of the bearing holder like they should. I used some grease to hold them in during assembly.